Added long to double typecast for division ops.

Added long to double typecast in addDuration method to increase precision after division operations.

Change-Id: I4cba5661c9b634db86d25b2286e7f9cd4fa84b6c
Signed-off-by: Lukas Sedlak <lsedlak@cisco.com>
Merge "Added long to double typecast for division ops."